.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "examples/02-constraints/pressurized_pipe.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_examples_02-constraints_pressurized_pipe.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_examples_02-constraints_pressurized_pipe.py:


Pressure constraint
~~~~~~~~~~~~~~~~~~~

This example illustrate the use the pressure constraint for the simulation of
a pipe under internal pressure and external pressure. The problem is treated
in 2D with plane strain assumption.

.. GENERATED FROM PYTHON SOURCE LINES 9-26

.. code-block:: Python


    import fedoo as fd

    # Pressure in MPa
    external_pressure = 0.1
    internal_pressure = 2
    radius = 200
    thickness = 20

    fd.ModelingSpace("2D")  # plane strain assumption
    mesh = fd.mesh.hollow_disk_mesh(radius, thickness, nr=5, nt=41)

    material = fd.constitutivelaw.ElasticIsotrop(200e3, 0.3)

    wf = fd.weakform.StressEquilibrium(material)
    solid_assembly = fd.Assembly.create(wf, mesh)








.. GENERATED FROM PYTHON SOURCE LINES 27-30

To find the nodes belonging to the boundary of the pipe, the
:py:meth:`fedoo.Mesh.find_nodes` method is used with the "Distance" criterion
from the center of pipe whose coordinates is [0, 0].

.. GENERATED FROM PYTHON SOURCE LINES 30-34

.. code-block:: Python


    ext_nodes = mesh.find_nodes("Distance", ([0, 0], radius))
    int_nodes = mesh.find_nodes("Distance", ([0, 0], radius - thickness))








.. GENERATED FROM PYTHON SOURCE LINES 35-51

The pressure requires to build a weaform over a surface Mesh. To
automatically build the required surface mesh from a set of nodes, with use
the :py:meth:`fedoo.contraint.Pressure.from_nodes` constructor.

Alternatively, we can use the
:py:meth:`fedoo.contraint.Pressure.from_elements` constructor from a set of
element to extract the external surface.

.. note::
  The from_nodes and from_elements constructor can't be used to apply a
  pressure over a shell structure because, as the shell mesh is a surface
  mesh, these constructors will extract linear mesh of the boundaries.
  To apply the mesh over a shell geometry, the
  :py:class:`fedoo.contraint.Pressure` constructor needs to be called.
  See the example
  :ref:`sphx_glr_examples_01_simple_spherical_shell_compression.py`

.. GENERATED FROM PYTHON SOURCE LINES 51-56

.. code-block:: Python



    ext_pressure = fd.constraint.Pressure.from_nodes(mesh, ext_nodes, external_pressure)
    int_pressure = fd.constraint.Pressure.from_nodes(mesh, int_nodes, internal_pressure)








.. GENERATED FROM PYTHON SOURCE LINES 57-59

Define a problem from the solid and pressure assemblies
The 3 assemblies are sumed.

.. GENERATED FROM PYTHON SOURCE LINES 59-64

.. code-block:: Python


    pb = fd.problem.Linear(solid_assembly + ext_pressure + int_pressure)
    pb.solve()

    pb.get_results(solid_assembly, "Stress").plot("Stress", "pressure", "Node")




.. image-sg:: /examples/02-constraints/images/sphx_glr_pressurized_pipe_001.png
   :alt: pressurized pipe
   :srcset: /examples/02-constraints/images/sphx_glr_pressurized_pipe_001.png
   :class: sphx-glr-single-img








.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.278 seconds)


.. _sphx_glr_download_examples_02-constraints_pressurized_pipe.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: pressurized_pipe.ipynb <pressurized_pipe.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: pressurized_pipe.py <pressurized_pipe.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: pressurized_pipe.zip <pressurized_pipe.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_